This paper presents the results from two prototypicality tests which aimed at obtaining evidence to prove that the differences in the representativity of indirect request and command utterances depend on both the centrality of the components of the respective cognitive models that are instantiated and the degree to which they are present in the utterances. This work is based on Thornburg and Panther's (1997) metonymic approach, which has been dealt with in depth by Pérez Hernández and Ruiz de Mendoza (2002). According to this approach, indirect speech acts are types of 'metonymy', that is, utterances that can evoke a particular 'Illocutionary Idealized Cognitive Model' through the expression of one of its components. The findings confirm the expected dependence and can be explained from the metonymyc point of view.